An additional suggestion to @Makigirl 's is to add a diffuse boost to the grass material when not receiving shadows. It would be in a blueprint, and I don’t know how to set that up.
There’s also the Distance Field Indirect Shadow feature. Enable that and set Min Visibility for it.
Thank you for your answers, unfortunaly the grass doesn’t seem to be affected by distance field (grass is generated via landscape material, using LandscapeGrassType, that’s maybe why).
I tested it using a PointLight with DistanceFieldShadows checked :
And the Mesh distance field view :
What would be your lighting setup for an open world with a day cycle?
Enable “Affect Distance Field Lighting” under Instance Settings, if it’s not yet. There’s also a setting in Landscape Grass Type > Grass Varieties called “Use Landscape Lightmap” which probably needs to be enabled to get the effect of the shadowing…but perhaps not. Distance field shadows are tricky, from what I know so far.
I can’t see changes with “Use Landscape Lightmap”… And for “Affect Distance Field Lighting”, I don’t find this option on LandscapeGrassType, but I have it on ProceduralFoliageSpawner (that I use with trees, and this fixed the DF Shadows on theses).
I tried to make a PFS to generate the grass (with affect distance field lightning) and this fixed the brightness of the grass, however it takes ages to generate + it cause a huge fps drop (from 190 to 87 fps)…
it could be other settings for the PFS are causing the long generation and fps drop…
how much grass is there? creating LODs could counteract the fps drop…
I’m not sure using PFS is the solution, it is intended to be used with trees… However I found a decent solution to my problem, on skylight, I turned “Lower hemisphere is solid color” back on, and I set a dark grey in DFAO tint, it’s not perfect but it seems to do the trick